The Fundamentals of Lead in Settled Dust

Lead based paint

According to the Environmental Protection Agency (EPA), millions of homes in the United States still contain lead paint. While people typically associate lead exposure with peeling paint chips in an older home, one hazard that can be overlooked is lead present in household dust. In this blog, we will discuss lead in settled dust and how it is sampled.

Lead Paint Basics

Lead paint was used in many homes across the country and coveted for its durability, longevity, and the ability to amplify the appearance of certain colors. Lead paint was banned by the federal government in 1978 after the health effects of lead exposure became more apparent. When lead paint is stable, encapsulated by layers of newer non-lead based paint, and not peeling it poses less of a health risk. The primary route of exposure for lead is via ingestion and the primary demographic affected by lead exposure are young children. If you wanted to know about how lead-based paint is tested please refer to our previous blog on the subject.

How Lead Dust is Generated

If the paint in the home looks stable and is not chipping, it does not necessarily mean there is no lead present in the dust. Housework or renovations that involve sanding or scraping of paint can generate lead dust even in paint that has levels of lead that are below the regulated limits. Lead dust is usually linked to driving up lead levels in children’s blood while many assume its due to ingesting paint chips. Lead dust is typically higher in concentration in areas of high contact such as window sills and window troughs, but can also be present on the floors. Lead dust can also be brought into a home by tracking lead-containing soil into a home.

Lead Testing Methodology

Lead dust testing is typically conducted if there a concern of a particular area in a property, a child developed lead poisoning, or if there was lead abatement or renovation occurring at a property. Lead dust testing involves using a sterile wipe to wipe down a horizontal surface with its dimensions documented. The common areas which are tested are floors, window sills, and window troughs. The wipes are then sent to an accredited laboratory where they are analyzed typically be flame atomic absorption analysis. This process involves dissolving the wipes in acid, and the resulting solution passing through a flame where its light spectra are analyzed which can determine the concentration.

Lead Dust Removal and Guidelines

Once elevated lead dust has been discovered, it should be removed by a licensed lead abatement professional. The process will typically involve containing the contaminated area, wet wiping, HEPA vacuuming, and sometimes chemical compounds are used. EPA guidelines are used to determine if lead levels are elevated;  however, local municipalities or states may have stricter guidelines. For example, the Illinois Department of Public Health (IDPH) has much more stringent guidelines than the EPA. The IDPH clearance level for lead on the floor is a quarter of the EPA’s regulated limit (10 µg/f2 vs. 40 µg/f2).

Conclusions

If there is concern about lead dust in an older home, especially where children are present or renovation activities were recently completed, lead dust testing should be conducted. When conducting a renovation we recommend hiring a firm that is trained and certified in the EPA’s Renovation, Repair, and Painting (RRP) rule which trains contractors on how to use lead-safe practices. At Indoor Science we offer lead-based paint testing and lead wipe testing. Lead in settled dust shows us how small containments can lead to greater health effects.

Jordan Thomas

Jordan Thomas

Jordan Thomas is a Project Manager that performs indoor air quality assessments with a specialty in asbestos and lead. Mr. Thomas holds a Bachelors of Arts degree in Earth Science from DePauw University. Jordan is an ACAC Council-Certified Indoor Environmentalist (CIE), Licensed Lead and Asbestos Inspector, Licensed Air Sampling Professional, and HAZWOPER certified. He also holds an asbestos microscopist certificate from the McCrone Research Institute. Prior to working at Indoor Science, Jordan worked as an Industrial Hygienist at Environmental Analysis, Inc and as an Asbestos/Lead Analyst at Metro Technology Laboratory. In his words… “While not in the field, I’m a Nu-Jazz and movie enthusiast.”

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